Field
Aspects of this disclosure generally relate to determining a response to a contact by a hand with a region of a touchscreen.
Description of the Related Art
A touchscreen combines the functions of an electronic visual display and a user interface by allowing a user to interact directly with an object displayed on a screen rather than indirectly through a keyboard, a mouse, a touchpad, or other type of user interface. Accordingly, touchscreens have been incorporated into a wide variety of devices including game consoles, video games, interactive tables, personal computers, tablet computers, personal digital assistants, smartphones, mobile phones, satellite navigation devices, and electronic books. The interaction is realized in the form of a touch of the object displayed on the screen. In response to the touch, an electronic processor of the device that has the touchscreen causes the device to perform an action in a manner associated with the object, the type of the touch, or both. Such actions include causing application programs to start or stop, causing information to be input to the device, and/or changing appearances of displayed objects.
Originally, a stylus or digital pen was used to interact with a touchscreen to protect the touchscreen from oil residue that might otherwise obscure the touchscreen if a finger is used for the interaction. However, more recently developed touchscreens not only include technology that lessens the impact of oil residue, but also are designed to support a variety of multi-touch gestures to increase the functionality that can be realized from using a touchscreen as a user interface. Such multi-touch gestures are characterized by the size of the area of contact with the displayed object, the duration of time of contact with the displayed object, the number of points of contact with the displayed object, and/or the direction(s) of movement along the screen. Among the multi-touch gestures that can be applied to a displayed object and recognized by current touchscreens are a tap (with one or two fingers), a double tap, a long press, a scroll (with one or two fingers), a pan, a flick, a pinch, a zoom (outward moving pinch), and a rotate. Despite these developments, a stylus or digital pen is often still used to interact with a touchscreen to facilitate a more precise indication of a point of a touch, particularly when the interaction involves writing or drawing.
Unfortunately, the increase in the variety of touch gestures complicates efforts to distinguish an intended touch of a touchscreen from unintended contact with the touchscreen.
There have been efforts to address this problem. One approach has been to incorporate a mechanism to designate a portion of a touchscreen to be unresponsive to touches. The mechanism is initiated by a selection by the user.
Another approach has been to incorporate a rejection algorithm into a device that has a touchscreen. The basis of the algorithm is an assumption that both a digital pen and a portion of a hand will rest on a touchscreen when a user is writing on the touchscreen. The algorithm is designed to try to distinguish the location of the touch of the digital pen from the location of the touch of the portion of the hand. The algorithm is initiated by a selection by the user. The selection is typically made when the user intends to write on the touchscreen with a digital pen. The algorithm is designed to try to ignore other touches of the touchscreen when the algorithm has been initiated by the user.
In a variation of this approach, the algorithm is designed to consider several factors to distinguish intentional from unintentional touches of the touchscreen. These factors include a number of points of touch on the touchscreen, whether the touches are sequential or concurrent, shapes of the points of touch, whether the shapes of the points of touch coincide with concurrent touches by a finger and a digital pen, a distance between the touchscreen and the digital pen, an angle between the touchscreen and the digital pen, an analysis of a grip position of the digital pen, and an analysis of a grip of a device that has the touchscreen.